rename SkBitmapChecksummer as SkBitmapHasher, and prepare for it to possibly use
some algorithm other than CityHash
Review URL: https://codereview.chromium.org/14170010

git-svn-id: http://skia.googlecode.com/svn/trunk@8639 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/utils.gyp b/gyp/utils.gyp
index 0048111..a14f585 100644
--- a/gyp/utils.gyp
+++ b/gyp/utils.gyp
@@ -57,8 +57,8 @@
 
         '../src/utils/SkBase64.cpp',
         '../src/utils/SkBase64.h',
-        '../src/utils/SkBitmapChecksummer.cpp',
-        '../src/utils/SkBitmapChecksummer.h',
+        '../src/utils/SkBitmapHasher.cpp',
+        '../src/utils/SkBitmapHasher.h',
         '../src/utils/SkBitmapTransformer.cpp',
         '../src/utils/SkBitmapTransformer.h',
         '../src/utils/SkBitSet.cpp',